Make a note of " MCR-1 ".
It is a buzz term that you will hear more about. We start our explanation of this, with a a basic review of microbiology....
Hello.... Hello?? Are you still awake? Stay with me.
Bacteria a living cells with cell walls made of carbohydrates (cellulose- a complex sugar).
Some have a fatty (lipid) membrane coating around the cell wall.
Inside, are most of the goodies that other cells have, organelles like mitochondria, cytoplasm, lysosomes, and nucleus to name a small familiar sample.
Inside the nerve centre of the bacteria is genetic material (genes) arranged in to long protein strands called chromosomes. This is where the bacteria gets its instruction to function and reproduce.
Unlike animals and plants that must mate with a male/female combination to reproduce, bacteria are asexual; boring I know, but true none the less. To divide into two identical copies of its self (producing offspring called Daughter cells), bacteria copies its chromosomes, then simply splits down the middle to form two new cells. 2 become 4 become 8 become 16 and so on ( look up you year 8 maths books , or have a chat to any Amway dealer to see how effective the power of duplication becomes.)
Anyhow I digress...
Given that bacteria make absolute clones of them self, you would think they can't change. But we know they do. They become resilient, and adapt to new environments. They mutate.
Enter the plasmid.
A plasmid is a rogue speck of genetic material that lives in the cytoplasm (watery juice) of the bacteria. Plasmids are genetic coded proteins that can become altered when a bacteria is exposed to an antibiotic (that should have killed it) but survives. Plasmids change, replicate on their own and translocate genetic information with genes inside the nucleus.
Now this surviving bacteria passes on this information to its daughter cells creating a bacteria that is now resistant to the antibiotic that previously would have killed its grand parents.
Are you still awake?
Ok. So plasmids don't just mutate and affect the host bacteria, but they can also share genetic information to other bacteria, even other species of bacteria. A Strep can share its resistance recipe with a Staph, or an E.coli with an Enterococci, or a Bacillus with a diplococcus.
Frightened yet?
Recently, an E.coli strain was discovered in a urine sample of an American woman with a UTI. This infection is resistant to every antibiotic. EVERY ANTIBIOTIC.
This drug resistant E.coli strain has a gene called MCR-1 which is harboured in the E.coli's plasmid.
This E. coli bacteria with the mcr-1 gene could pass its plasmid and gene to another superbug with other mutations-- creating a truly super-superbug that resists all known antibiotics.
The bio surveillance role that nurses and doctors have was always important, but this is going to have implications on infection control practices going forward.
I'm off to wash my hands ... again!
No comments:
Post a Comment